The present invention relates to protective devices for wiring and cable, and more particularly to a flexible bushing that can be easily and quickly installed in holes cut in steel and the like structural members the peripheral surfaces of which holes tend to damage inserted wiring and cable during installation.
In the installation of wiring in buildings utilizing steel studding, it is common practice to drill holes in the steel studding at all required locations to accommodate the passage of electrical and other wiring. While this method provides a sound construction technique and is generally highly protective of wiring insert through the steel studding or other steel structural member, it is not uncommon for wiring to be damaged while being pulled during installation as the sharp and often erose edges of the freshly drilled hole are drawn across the wiring surface during such installation. With the proliferation of the use of steel structural members even for residential construction, and the use of larger and larger quantities of light gauge telephone, communication and low voltage wiring in all structures, this problem has become even more wide spread.
Thus, there exists a need for an inexpensive and easy to use and install device that can protect wiring and cabling being pulled through holes in such structural members during the pulling operation.
It is therefore and object of the present invention to provide an inexpensive device for the protection of wiring and cabling being pulled through holes in steel structural members.
It is another object to provide such a protective device that is inexpensive and very easy to install.
According to the present invention, there is provided a unitary protective bushing produced from a resilient plastic and comprising an elongated base having at least two distinct widths at either end, opposed longitudinal edges, and two rows of spaced apart teeth extending in splayed relationship from said longitudinal edges. Because of the distinct differences in the width of the base, the two rows of teeth are spaced apart different distances along the base such that when turned upon itself the teeth of the bushing along the narrower width nest within the teeth along the wider width. Because of the resilience of the plastic material, the bushing can be turned upon itself, inserted into a hole in steel structural member such that the teeth loosely engage either side of the periphery of the hole and the resilient plastic causes the base to spring open until the inside surface of the base contacts the inside periphery of the hole and the teeth engage the surfaces of the stud about either side of the periphery of the hole. The bushing is then reliably engaged about the inner periphery of the hole by virtue of the teeth engaging the periphery of the hole and being held in place by the resilience of the base. Wiring or cabling can be then pulled through the hole without the danger of damage to thereto.